Pin-tumbler lock



April 28, 1964 J. HINES PIN-TUMBLER LOCK Filed Sept. 10, 1962 INVENTOR. JOHN H/NE 5 United States Patent 3,130,573 PIN-TUMBLER LUCK John Hines, South Norwalh, Conn, assigns: to The New England Lock and Hardware Co., South Nor-walk, Conn, a corporation of Connecticut Filed Sept. 10, 1962, Ser. No. 222,478 7 Claims. (Cl. 70-417) This invention relates to improvements in pin-tumbler locks of the kind comprising a cylinder and a key barrel or plug which is mounted for ot-ating in the cylinder and when rotated actuates the locking mechanism of the lock. In such locks the cylinder and the plug have cooperating recesses for pin tumblers, drivers and coil springs, and the plug is formed with a key slot. When the proper key is inserted it will position the pin tumblers so that they will contact the drivers respectively at the outer peripheral surface of the plug. With the line of parting between the pin tumblers and the drivers thus positioned the plug is free to rotate as the key is turned.

In connection with locks of the above mentioned kind it has been suggested to make the outer faces of the cylinder and the plug of hardened steel, or to provide a hardened steel barrier between the cylinder and plug face plates and the tumbler pins arid drivers to protect the pins and drivers from being cut oii or otherwise damaged by a drilling tool entered through the face of the lock in the plane of the pins and drivers. But with the drilling tools now available, which are capable of drilling through hardened steel or other armor plate employed whether in the form of a disc inseit or a pin or screw, the protection means which have been previously used are no longer satisfactory. In fact the need for a better way to protect pin-tumbler locks has now existed for many years but has not previously been filled.

It is the object of this invention to provide simple and efiective means for giving pin-tumbler locks protection against the hardest and strongest of modern boring tools.

This invention will best be understood if the following description is read in connection with the accompanying drawings in which:

FIG. 1 is a front view in elevation of the pin tumbler lock;

FIG. 2 is a longitudinal cross-section taken on the line 2-- 2 of FIG. 1;

FIG. 3 is a vertical cross-section taken on the line 33 of FIG. 2; and

FIG. 4 is a front view in elevation of a modification of ring means extending around the rotatable member.

In the embodiment of the invention illustrated herein a cylinder has a face plate or escutcheon 12 and an opening 13 extending through it in which is mounted for rotation a plug 14 the forward end or face of which is flush with the face plate of the cylinder. A number of recesses 16 are provided in the cylinder extending from the opening 13 and in alignment longitudinally of the cylinder. A number of similarly spaced recesses 18 are provided in the plug 14, adapted to be aligned with the recesses 16 in the cylinder, when the plug is rotated to its position for interlocking with the cylinder. The recesses 18 in the plug open into the top of key slot 17 which extends longitudinally of the plug and through its face plate. Coil springs 29 are disposed in the recesses 15 respectively, and tumbler-pins 22 are mainly disposed in the recesses 18 and drivers 24 are mainly disposed in 3,1305% Patented Apr. 28, i94

the recesses 16, but it will be understood that springs 2% push the drivers toward the plug and they may enter partly into recesses 18 when recesses 16 are respectively aligned with recesses 18, depending upon the position of the tumbler-pins. When no key or other tool is inserted in the key slot 17 the tumbler-pins 22 will be wholly contained within the plug and will rest on the bottom of recesses '18, but when a key is inserted in slot 17 the pins 22 be raised and will rest on the contoured upper edge of the key, and, depending on the height of the key at the points of contact, one or more of the pins may extend partly into the aligied recesses 16.

The proper key for the lock has its upper edge contoured so that the pins will be disposed entirely within recesses 18, and the drivers will be disposed entirely within the recesses 16, and the interface between all the pins and all the drivers, which is referred to herein as the line of panting, will be at the periphery of the plug, thus allowing the plug to rotate within the cylinder and moving the recesses 18 out of alignment with recesses 16, and thus unlocking the lock. However, when a key having a different upper edge contour is entered in slot 17 either one or more of the tumbler pins 18 will be forced by the key partly into recesses 16, or, one or more of the driver pins will be forced by springs 20 into recesses 18, or one or more tumbler pins and one or more driver pins will be moved across the line of parting and so be disposed partly in a recess 16 and partly in a recess 18, and thus prevent rotation of the plug within the cylinder.

In the face of the lock, or, preferably and as shown herein, in barrier means between the face of the lock and the recesses 16 and 18, in the plane which is common to both tumbler pins 22 and driver pins 24 when the plug and cylinder are in interlocking position, a seat 26 is provided which is a bearing adapted to receive a member 28 for rotation therein. The member -28 may be a disc or a ball. The important thing is that the member 28 is freely rotatable. I have found that when a drill contacts the rotatable member '28 the frictional contact causes member 28 to rotate and this action throws the drill to one side causing it to bend or break. Even if the drill should then penetrate further it would not contact the tumbler pins or the driver pins, at or adjacent to the line of parting and the lock would not fail.

Of course if the outer face of rotatable member 28 is convex the form of its surface will aid in deflecting a boring tool, but even if its outer face is flat and it is rotatable in a plane at right angles to the axis of the plug it is impossible to hold the boring tool against it long enough to drill through it. Instead member 28 rotates immediately when contacted by the drill and this action throws off the point of the drill which, in repeated tests I have made, inevitably bends or breaks even when made of the hardest materials available, and irrespective of the speed of rotation of the drill.

Extending over and at least partly around the rotatable member 28 is a protective member 36 the face of which is crowned. Preferably member 30 is an annular member or ring of hard material extending around the forward end of the plug 14, which may be reduced in cross section to provide space for it. As shown herein, plug 14 is cut away adjacent its front end and in the space thus provided two semi-circular barrier inserts 32 and 34 are provided. Member 34- has a recess 35 to receive a rotatable member 28 inserted into it from its side. Member 32 has a tapering cut out 36 narrowing toward the front, to coact with the recess in member 34 in providing a seat for member 28. Members 30, 32 and 34 are preferably made of vlery hard material and are shown as made of hardened stee The rotatable member 28 is disposed between the top of the key slot and the periphery of the plug. This places the uppermost portion of member 28 substan tially in alignment with the periphery of the plug and with the line of parting between the tumbler and driver pins. The member 36 extends in an are over and at least partially around the rotatable member 28, and close to member 28. As illustrated herein member 30 is a ring with a flange 30a at its rear edge which abuts against the rear face of member 32 thus preventing it from being removed through the face of the lock. The other face of the ring is crowned, and preferably the ring is circular in cross section.

The member 30 coacts with the rotatable member 28 to divert the point of a drill away from the line of parting between the tumbler and the driver pins, and to bend or break the drill, or in any event prevent the drill from making a bore where the bore will make it possible to unlock the lock without the insertion of the key which has its upper edge contoured for that particular lock.

If the end of the drill contacts the rotary member 28 the latter will be caused to rotate and this rotation will throw off the point of the drill with the result that it will be bent or broken, and even if it should not be bent or broken it would be directed through the look at an angle such that it would not make a bore along the periphery of the plug or anywhere resulting in unlocking of the lock.

If the leading end of the drill strikes the crowned face of the ring 30 it will be thrown either outwardly, (in which case it will be bent or broken, or even if not damaged, it will make a bore which will not damage the pins along the line of parting between the tumbler pins and the driver pins, or anywhere resulting in unlocking the lock) or it will be deflected inwardly, and if this occurs where a bore might result in unlocking of the lock it will be deflected onto the rotary member 28, in which case the action will be as described above and the drill will be bent or broken, or, in any event, it will be prevented from making a bore which will permit the lock to be unlocked without the use of the proper key.

I have obtained excellent results with a lock of the kind described above in which the diameters of the plug 14, the rotatable member 28, and the ring 30, although varying in size in accordance with the size of the lock, are related substantially in the relative proportions of an embodiment of the invention in which the diameter of the plug is substantially 7 of an inch, the

diameter of the rotatable member is substantially of 7 an inch, and the outside diameter of the ring is of an inch.

There has thus been disclosed an embodiment of the invention in which the above stated object is accomplished in a thoroughly practical way.

What I claim is:

1. In a lock of the cylinder type comprising a cylinder, a plug mounted for rotation in the cylinder and having a longitudinal key slot, recesses in the cylinder and plug respectively disposed so that they are aligned when the plug is in a predetermined position rotatively relative to the cylinder, tumbler pins wholly contained in the plug recesses respectively except when elevated by the insertion of a wrong key in the key slot and thereby caused to enter partially into the recesses of the cylinder respectively when the recesses in the plug and cylinder are radially aligned, coil springs in the recesses in the cylinder, and driver pins acted on by said springs respectively but wholly contained in the cylinder recesses respectively except when the recesses in the plug and cylinder are aligned and the tumbler pins are not elevated to the periphery of the plug, the combination of a member disposed in advance of, and aligned with, the pins, and rotatable in response to the contact of the leading end of a rotating drill, and an annular ring of hardened material surrounding the rotatable member and coacting with the rotatable member to deflect a drill from penetrating the lock where the result would be to destroy the interlock between the plug and the cylinder.

2. The device claimed in claim 1, in which the rotatable member is disposed within, and the surrounding annular ring is anchored by means provided between the face plate of the lock and the tumbler pins.

3. A pin tumbler lock comprising a cylinder and plug, the plug being mounted to turn in the cylinder and having its forward end substantially flush with the face of the cylinder, the plug being slotted with a longitudinally extending key slot, the plug having a number of re cesses disposed in a line longitudinally of the plug with their lower ends opening into the key slot from the top, and the cylinder being bored with a series of recesses extending radially from the interface between the cylinder and the plug and adapted to be aligned with the recesses in the plug, tumbler pins and driver pins in said recesses respectively, and yielding means maintaining contact between the lower ends of the driver pins and the upper ends of the tumbler pins respectively, a rotatable member, barrier means between the face of the plug and the tumbler pins, a seat in the barrier means for mounting the rotatable member, and a protective ring surrounding the plug adjacent its forward end and anchored behind the face of the plug, said ring and said rotatable member cooperating to prevent a drill from entering the lock and boring a hole adjacent the periphery of the plug and in alignment with the tumbler pins.

4. A cylinder lock comprising a cylinder having an opening therein for a plug, and a number of recesses extending radially from the opening and disposed in line longitudinally of the opening, a plug mounted for rotation in the opening and having a key slot, and recesses in the plug corresponding in number and spacing to the recesses in the cylinder, and adapted to be respectively aligned with the recesses in the cylinder when the plug and cylinder are in locking relation, spring means, drivers and pin tumblers disposed in each of the combination of recesses comprising a recess in the cylinder and an aligned recess in the plug, and a rotatable member disposed in advance of the tumbler pins and drivers and in the plane common to them when the plug and cylinder are in locking relation, an annular protective member the face of which is crowned, and projects in advance of the rotatable member and extending at least partly around the rotatable member, the rotatable member and the crowned face of the protectivemember being each adapted to deflect a drilling tool.

5. As a new article of manufacture, a pin tumbler lock having a member mounted for rotation in a plane which is at right angles to the axis of the plug, the uppermost surface of the member being substantially aligned with the periphery of the plug, and an annular protective member which extends partly around the rotatable member and comprises a drill resisting forwardly extending flange the outer surface of which is crowned.

6. As a new article of manufacture, a pin tumbler lock having a drill resisting member mounted for rotation and substantially aligned with the tumbler pins, and an annular drill resisting protecting ring member at least partly encircling the rotatable member and projecting forwardly beyond the rotatable member, the forwardly projecting portion of said ring member being crowned in cross section. V

7. As a new article of manufacture, a pin tumbler lock having a member mounted for rotation in a plane which is at right angles to the axis of the plug, the uppermost surface of the member being substantially aligned with the periphery of the plug, and an annular protective member which extends partly around the rotatable member and comprises a drill resisting forwardly extending flange the outer surface of which is crowned, 5

the diameters of the plug and rotatable member, and the cross section of the forwardly projecting flange portion of the annular protecting member, being substantially proportional to the following sizes; plug substantially W1 of an inch, rotatable member substantially of an inch and the forwardly projecting flange portion of the annular protective member substantially /1 of an inch.

References Cited in the file of this patent UNITED STATES PATENTS 1,228,445 Janes June 5, 1917 1,488,925 Hurd Apr 1, 1924 1,548,131 Freysinger Aug. 4, 1925 FOREIGN PATENTS 6,783 Great Britain Mar. 19, 1912 

1. IN A LOCK OF THE CYLINDER TYPE COMPRISING A CYLINDER, A PLUG MOUNTED FOR ROTATION IN THE CYLINDER AND HAVING A LONGITUDINAL KEY SLOT, RECESSES IN THE CYLINDER AND PLUG RESPECTIVELY DISPOSED SO THAT THEY ARE ALIGNED WHEN THE PLUG IS IN A PREDETERMINED POSITION ROTATIVELY RELATIVE TO THE CYLINDER, TUMBLER PINS WHOLLY CONTAINED IN THE PLUG RECESSES RESPECTIVELY EXCEPT WHEN ELEVATED BY THE INSERTION OF A WRONG KEY IN THE KEY SLOT AND THEREBY CAUSED TO ENTER PARTIALLY INTO THE RECESSES OF THE CYLINDER RESPECTIVELY WHEN THE RECESSES IN THE PLUG AND CYLINDER ARE RADIALLY ALIGNED, COIL SPRINGS IN THE RECESSES IN THE CYLINDER, AND DRIVER PINS ACTED ON BY SAID SPRINGS RESPECTIVELY BUT WHOLLY CONTAINED IN THE CYLINDER RECESSES RESPECTIVELY EXCEPT WHEN THE RECESSES IN THE PLUG AND CYLINDER ARE ALIGNED AND THE TUMBLER PINS ARE NOT ELEVATED TO THE PERIPHERY OF THE PLUG, THE COMBINATION OF A MEMBER DISPOSED IN ADVANCE OF, AND ALIGNED WITH, THE PINS, AND ROTATABLE IN RESPONSE TO THE CONTACT OF THE LEADING END OF A ROTATING DRILL, AND AN ANNULAR RING OF HARDENED MATERIAL SURROUNDING THE ROTATABLE MEMBER AND COACTING WITH THE ROTATABLE MEMBER TO DEFLECT A DRILL FROM PENETRATING THE LOCK WHERE THE RESULT WOULD BE TO DESTROY THE INTERLOCK BETWEEN THE PLUG AND THE CYLINDER. 